The present invention relates to slide out racks or shelves of metallic construction used for supporting objects in enclosures such as ovens, refrigerators, cupboards and the like.
Oven racks are generally of wire frame construction and are designed to slide over horizontal ribs at spaced heights in the opposite side walls of the oven so that they can be removed for cleaning or for replacing at a different height for a faster or slower cooking time. The racks are generally rectangular, with a surrounding peripheral frame and a series of spaced parallel support rods or wires extending between two opposite sides of the frame. The spaced wires form a support surface for food and other articles placed on the shelf or rack, and may extend from the front to the rear or between opposite sides of the oven when the rack is in place. Normally a raised stop bar is provided at the rear of the shelf to prevent articles such as pots, pans, dishes, plates and the like from being pushed too far onto the shelf. Downwardly angled hooks are also often provided at the rear end of the rack for positively engaging around the oven ribs for added stability of the rack to prevent it from tipping when the weight of articles placed on the rack is unevenly distributed. Such hooks are normally arranged to engaged suitable stops on the guide ribs as the rack is being removed from the oven to prevent the rack from being pulled straight out of the oven. Normally the forward end of the rack must be raised to allow the hooks to slide over the stops, which are generally in the form of thickenings of the ribs such as bumps or ridges on the lower side of the ribs. Refrigerator shelves are normally of similar construction.
One problem in such racks is providing sufficient rigidity to support an average weight of articles while not adding too much weight to the construction to make it both cumbersome to handle and relatively expensive. Where a stop bar is added to the rear of the rack this is normally an extra rod welded across the rear part of the peripheral frame member, which adds to the weight, expense and complexity of the construction.
In one prior art construction of this type the rack comprises an outer frame member of rectangular shape, and a series of parallel support rods or wires extending from opposite front and rear limbs of the frame member to form a support surface. The side limbs of the frame member engage over guide ribs in the side walls of the oven, and a raised stop bar extends between the opposite side arms at the rear of the frame. The stop bar is formed with hook like projections at its opposite ends which project below the level of the side arms such that when the rack is in position in the oven the opposite guide ribs are engaged between the respective side arm and hook like projection to add strength to the shelf and restrict its sliding movement out of the oven. Even when the shelf is pulled slightly out of the oven the support surface will still be relatively stable due to the hooks engaging under the guide ribs to prevent the rear end of the rack from pivoting upwards due to the weight of the rack and anything supported on the rack.
This known rack construction requires the addition of an extra member at the rear of the rack to form the stop bar and retaining hooks, adding to the amount of material required in the rack construction and thus increasing the cost.